1. Field of the Invention
The present invention relates to an image recording method and apparatus for digital-recording a plurality of frames of image data, an image processing apparatus, and an image reading method for reading an image.
2. Related Background Art
Conventionally, a technique for compressing a plurality of frames of image data, and recording compressed image data on a recording medium is known.
As an example of such a technique, a compression method for orthogonally transforming input image data, and quantizing converted coefficients, e.g., a compression method called a JPEG method, is known.
When a plurality of input image data are compressed to fixed-length data using such a compression method, if the code quantity assigned per image is represented by L, a two-pass compression method is repetitively performed from the beginning to the end of continuous photographing operations of n images, to keep code quantities L.sub.1 to L.sub.n of the n images equal to or smaller than the code quantity L.
However, in this prior art approach, since two-step coding is performed in each photographing operation in a continuous recording mode, the data compression operation requires much time, and limits any increase in continuous recording speed which might otherwise be achievable.
More specifically, in the above-mentioned method, in order to limit input image data to a predetermined code quantity, compression must be attempted several times while changing quantization coefficients, resulting in the long data compression time. In particular, this method limits an increase in speed in continuous photographing operations.